SDI out to the big screen

i flew up to the Gold Coast for a camera test and when i outputted SDI from my camera to link to a big screen above the Lecture theatre stage it produced a horizontal difference in the image; ie the top half was good, but the bottom half produced a weird drag in the image. If i panned or tilted i could see the people in a comet tail effect be dragged around the screen. I changed the shutter rate but this did not change a thing. Any thoughts?

Cheers
Drewsta